Grass and vegetation mowing equipment including lawn and garden tractors, zero-turn or spin-turn mowers, and various other mower configurations may have an internal combustion engine or other power supply with a generally horizontal crankshaft, a transmission, and one or more rotary cutting blades mounted to generally vertical shafts. A gear box may change the transmitting direction between the engine and cutting blades. Each cutting blade may be positioned under a mower deck, and the gear box may be located on or above the upper surface of the mower deck.
A gear box houses pairs of spiral bevel gears to change the transmitting direction from an input shaft to an output shaft. For example, spiral bevel gears and sections of shafts may be disposed at right angles to each other, to change the transmitting direction from a generally horizontal direction to a generally vertical direction.
A mower operator may be seated or standing on a platform that is on or above the upper surface of the mower deck. The platform may be directly or generally over the gear box. The height of the platform and seat over the deck may result in a high center of gravity for the vehicle and operator, which may present an instability problem. Additionally, the platform may be at such a height above the ground surface so that some operators may find it awkward to step up onto the platform.
A mowing device is needed with improved stability. A grass mower is needed with an operator platform and seat at a lower height, with a lower center of gravity. A gear box is needed that will help improve the stability of such a vehicle, and lower the center of gravity, operator platform, and seat.